According to my book the early 730 had a different camshaft than the latter. The difference was noted on a decal on the valve cover, worn off on mine. There are different settings for each style of camshaft. The picture below from my service manual explains the difference and the settings. My parts book, which is a A906, lists a A23495 as the camshaft number, which doesn't match up to the numbers on the decals in the service book. My tractor serial # is 8220271 which makes it a 1963. The engine serial # is 2036278. On other parts a differentiation is noted at certain serial numbers but nothing is given on this. Over the course of production, it appears there were three models/changes and mine falls in the middle. Other than pulling the camshaft out, is there some way to determine which camshaft I have?